[PATCH RESEND] netfilter: remove unused variable

[PATCH RESEND] netfilter: remove unused variable

[Michal Nazarewicz]

The nfmsg variable is not used (except in sizeof operator which does
not care about its value) between the first and second time it is
assigned the value.  Furthermore, nlmsg_data has no side effects, so
the assignment can be safely removed.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Patrick McHardy <kaber@trash.net>
---
 net/netfilter/nf_tables_api.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index f93b7d0..9c56adc 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2521,7 +2521,6 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
 	u32 portid, seq;
 	int event, err;
 
-	nfmsg = nlmsg_data(cb->nlh);
 	err = nlmsg_parse(cb->nlh, sizeof(*nfmsg), nla, NFTA_SET_ELEM_LIST_MAX,
 			  nft_set_elem_list_policy);
 	if (err < 0)
-- 
1.8.4

Re: [PATCH RESEND] netfilter: remove unused variable

[Pablo Neira Ayuso]

On Wed, Jan 01, 2014 at 06:27:19AM +0100, Michal Nazarewicz wrote:
> The nfmsg variable is not used (except in sizeof operator which does
> not care about its value) between the first and second time it is
> assigned the value.  Furthermore, nlmsg_data has no side effects, so
> the assignment can be safely removed.

Applied with minor glitch, see below.

Thanks.

> Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
> Cc: Patrick McHardy <kaber@trash.net>
> ---
>  net/netfilter/nf_tables_api.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
> index f93b7d0..9c56adc 100644
> --- a/net/netfilter/nf_tables_api.c
> +++ b/net/netfilter/nf_tables_api.c
> @@ -2521,7 +2521,6 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
>  	u32 portid, seq;
>  	int event, err;
>  
> -	nfmsg = nlmsg_data(cb->nlh);
>  	err = nlmsg_parse(cb->nlh, sizeof(*nfmsg), nla, NFTA_SET_ELEM_LIST_MAX,

mangled this patch to use sizeof(struct nfgenmsg) instead. That change
is not required from the semantic point of view, of course, but for
readability reasons I think it's better not to refer to a variable
that is not used in that context.

>  			  nft_set_elem_list_policy);
>  	if (err < 0)
> -- 
> 1.8.4
> 

Re: [PATCH RESEND] netfilter: remove unused variable

[Michal Nazarewicz]

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On Sat, Jan 04 2014, Pablo Neira Ayuso wrote:
> On Wed, Jan 01, 2014 at 06:27:19AM +0100, Michal Nazarewicz wrote:
>> The nfmsg variable is not used (except in sizeof operator which does
>> not care about its value) between the first and second time it is
>> assigned the value.  Furthermore, nlmsg_data has no side effects, so
>> the assignment can be safely removed.
>
> Applied with minor glitch, see below.

Thanks.

> Thanks.
>
>> Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
>> Cc: Patrick McHardy <kaber@trash.net>
>> ---
>>  net/netfilter/nf_tables_api.c | 1 -
>>  1 file changed, 1 deletion(-)
>> 
>> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
>> index f93b7d0..9c56adc 100644
>> --- a/net/netfilter/nf_tables_api.c
>> +++ b/net/netfilter/nf_tables_api.c
>> @@ -2521,7 +2521,6 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
>>  	u32 portid, seq;
>>  	int event, err;
>>  
>> -	nfmsg = nlmsg_data(cb->nlh);
>>  	err = nlmsg_parse(cb->nlh, sizeof(*nfmsg), nla, NFTA_SET_ELEM_LIST_MAX,
>
> mangled this patch to use sizeof(struct nfgenmsg) instead. That change
> is not required from the semantic point of view, of course, but for
> readability reasons I think it's better not to refer to a variable
> that is not used in that context.

Works for me, and 

	err = nlmsg_parse(cb->nlh, sizeof(*nlmsg_data(cb->nlh)), nla,
			  NFTA_SET_ELEM_LIST_MAX, nft_set_elem_list_policy);

would probably be an overkill. ;)

>>  	if (err < 0)
>> -- 
>> 1.8.4

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
ooo +--<mpn@google.com>--<xmpp:mina86@jabber.org>--ooO--(_)--Ooo--

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